Question 1: I'm playing FFX PAL version. It's actual fps limit is 50, and my screen refresh rate is 60hz, so 50 fps looks like it's slow. So I manually limit it to 60, but that's like %120 of the game's speed, and with ZeroSPU2 Sound Plug-in's Time Stretching enabled, some dialogs sound too fast.
Can I solve that problem by converting my game to NTSC, thus running it at %100 speed or will it stay the same?

Question 2: Did anyone realise that with 8x AA or higher, the letters and some shapes look choppy and crippled while at menu/load screen? Is there a way to fix that without turning off AA or should I live with it? Here are two screenshots to show what I mean.

a pal game at 50 fps is not slow, it's exactly as fast as it's supposed to be. no need to patch anything for that. the refresh rate of your screen is rather irrelevant, if your monitor supports 120hz, it doesn't mean your game has to run at this exact fps

and you can disable "texture filtering" to avoid such texture upscaling artifacts.

1) It really shouldnt look like it's slow, it's "full speed" changes to 50fps ntsc or 60fps pal so speed should be the same regardless of pal or ntsc as soon as it's 100%

2) Games are designed for a specific resolution with no AA, zerogs's AA increases the game's internal resolution so those glitches are expected, GSdx's AA also adds a filter so it's expected as well, in most case only native or 0xAA should come bug free but too low resolution.

It should unless there is a bug creeping around somewhere. If you're running 50fps but the game feels like it's going to slow, make sure you don't have VU Cycle steal turned too far to the right. It should be at slight or moderate except in vary rare situations (like SotC) otherwise that will cause slowdowns even with 100% run speed.

...believe me my friend PAL is 50fps & NTSC is 60fps & if you get 100% speed in emu, that's the way it should & it is running on PS2, ...& if it bother's you that you're monitor is running on 60Hz, just enable V-Sync in options, & you won't have any problem except that you must have realy fast CPU xD...

Most PAL ports of games are in fact just 50hz versions of the original 60hz games -- in that they are running at about 85% of their "correct" speed and as such feel "slow." The only part that the games typically have adjusted is the sound. While the video runs 50hz, the music and sndfx run regular speed. This is how the games are designed, and so that is how PCSX2 emulates them.

(in the future I plan to add an option for speedhacking PAL games to 60 hz while retaining the correct audio playback speeds, but's low on my lengthy todo list...)